Follow Us!

Advertisement

Author's Featured Photo

Flight Attendants Sue Boeing Over Alleged Exposure to Fumes. Is There a Secret Menace in Cabin Air?

June 24, 2015

FOUR ALASKA AIRLINES cabin attendants have filed a lawsuit against Boeing alleging exposure to fumes during a Boston to San Diego flight aboard one of the carrier’s 737s. All four say they became ill, two of them to the point of unconsciousness. This is the latest in an on-again off-again series of complaints claiming that potentially dangerous engine fumes can be drawn into a plane’s cabin via the air conditioning system.

I’m not at all dismissing this issue as frivolous, but there are aspects to the Alaska story that make me curious. For example, the idea that four flight attendants became ill, and two of them were rendered unconscious, yet not a single passenger was affected. How is that possible? What were the passenger experiences on this flight, and why have none of them come forward?

According to the flight attendants’ lawyers, this is because the women had been on the plane longer than the passengers, including time spent in the cabin prior to boarding. Maybe, but one problem with that explanation is that the engines aren’t running when a plane is at the gate. Prior to boarding, conditioned air (cold or heated) is normally supplied through an external source; or, less commonly, via the plane’s APU, a small auxiliary engine located in the rear fuselage under the tail.

That’s not to say this didn’t happen, or that the “fume event” phenomenon doesn’t exist. But if and when it does occur, it’s unusual. In normal operation there is no mix between engine fluids — fuel, oil or hydraulics — and the air conditioning system. On the whole, cabin air is exceptionally clean.

(Note: It’s not uncommon to smell fumes for a few moments during engine start, especially with crosswinds or tailwinds. This is is due to exhaust being drawn into the exterior air conditioning inlets, and is otherwise unrelated to the controversy in question. It usually subsides once engine power stabilizes.)

And I’m unsure what makes this problem particular to Boeing planes, if in fact it is. Airbus and other manufacturers similarly use engine “bleed air” to power pretty much all of a plane’s pneumatics: cabin pressurization and air conditioning, anti-icing, etc. Of all mainline Boeing and Airbus models, Boeing’s 787 is the only one that doesn’t rely on engine bleed. It’s possible, once you get into the details of the systems, that there’s something in the design of Boeing’s other planes that allows burned oil to seep into the plumbing when and where it should not.

And if so, to me the bigger concern isn’t the very rare incident where fumes are so powerful that people are made immediately sick, or worse, but the effects of long-term exposure to smaller trace amounts. According to a British study, fume events occur on approximately .05 percent of flights. Their criteria isn’t made clear, but in some ways, and especially for those of us who fly all the time, the possibility of repeated small-scale exposures makes the phenomenon more worrying rather than less. And while any exposure is potentially harmful, how do airborne levels of such compounds stack up against those that people endure routinely in other settings — for example in their cars, when driving in heavy traffic? We are exposed to potentially unsafe chemicals everywhere: from the air we breathe,from the food we eat, from the plastics in thousands of consumer products and materials.* How does this compare? Frankly, as a pilot, I’m more worried about radiation exposure than about engine fumes.

For what it’s worth, I’ve flown Boeing planes for the better part of ten years as a crewmember, and of course I’ve been flying on them my whole life as a passenger, and I have never once knowingly experienced one of these “fume events,” and neither has anybody I know. Until this week you’d have been hard pressed to find an airline pilot or flight attendant who’d ever heard of the issue.

That doesn’t mean it’s not real, or that it doesn’t deserve a close look, but I disagree with any suggestion that the air on planes is categorically unsafe for the average flyer.

FOR MORE ABOUT THE FACTS AND FALLACIES OF CABIN AIR, SEE MY EARLIER DISUCSSION HERE.

23 Responses to “Fuming Over Fumes”

The smell is like really dirty sock smell.
I have smelled it got sick.
Been sick for years until I heard of this fume problem. Everything added up of my symptoms and timeline of illness.
The smell you don’t forget.
I have all my flight days and 250 plus pages of medical records.

I just got off a boeing landing in Denver with a massive headache. I am sensitive to fumes and although there have been occasional problems nothing like tonight when my spouse who can’t ever smell a thing said yes you are not imagining it even I can smell the fumes. OUr eyes were burning and I think we were all so happy to get off a trip that started with us being asked to evacuate the airport in dallas due to a potential fire. I am sure the airline attendents were telling the truth. Companies try to hide issues like fumes all the time for insurance reasons. If I had been on the airplane much longer I can guarantee I would have been very ill.

I am a retired pilot, airline safety professional and very involved with cabin fumes. My daughter, a long serving flight attendant has been injured by various fume events. The problem for flightvattendants is TILT (toxicant induced long term) exposure to organophosphate toxins in the engine oil. For some, injury comes fast from a major oil leak. For most, immunity becomes overburdened after years of low level exposure to small leaks.
This is a secret kept by the airlines, the FAA and EASA, etc. No cost effective fix has yet been found./

Without wishing to argue the point, I do believe that some 777 engines require an organophosphate-including oil. Jet engines use an interference seal (basically a tiny gap between the rotating and static bits) which, by their very nature, allow a small leakage of oil into the airstream. It’s often been alleged that worn and enlarged gaps have been responsible for neurological effects in crews on the type, though not to my knowledge on 737s.

Frankly, as a pilot, I’m more worried about radiation exposure than about engine fumes.

Yes, me too, especially when I fly over the poles, but of course I get nowhere near the exposure aircrew do. Seems odd to me that they don’t monitor exposure for crew like they do for, say, nuclear power plant workers.

The National Institute for Occupational Safety and Health and the Bureau of Epidemiology of the Center for Disease Control investigated episodes of red spots appearing on the skin of flight attendants during various Eastern Airlines flights in the first three months of 1980. Review of 132 cases reported during January and February showed that 91 different flight attendants had been affected; 96% of cases had occurred on flights between the New York and Miami metropolitan areas, and 90% on a single type of aircraft. Although some reports mentioned burning, nausea, and headache in association with spots, most reports involved only the occurrence of bright red spots that could be wiped or washed off. Studies of work practices and procedures of flight attendants revealed that the red spots were caused by red ink flaking off the life vests during demonstrations of the use of the vests in preflight safety instructions. The demonstration vests were labelled with ink containing a litholrubine chrome molybdate orange pigment. Following removal of the implicated vests from all Eastern Airlines aircraft, no further cases have appeared.http://www.ncbi.nlm.nih.gov/pubmed/7234691

It ‘s amazing what people fear and will sue over with little or no evidence, but companies and government “experts” have been wrong often when they call something is safe – look at 9/11 and the health issues for those cleaning up ground zero – the were told it was safe. Hopefully logic and science will prevail in the lawsuit, but don’t hold your breath.

I’ve always wondered about radiation – you are above about 80% of the atmosphere at the level planes cruise – I have heard an average flight (whatever that is) you get the equivalent of a couple of x-rays. There are all sorts of electromagnetic rays hitting us, and they are stronger without atmospheric protection – I don’t know if there are any studies on this??? Anyone know? I know they watch for sunspots on polar flights.

Patrick, have you ever been measured with a geiger counter? Hopefully you do not glow at night. Nothing like you but I’ve been on nearly 2,000 flights and my wife thinks that mixed with a little wine the radiation explains a lot about me.

I have brought a geiger counter onto a plane. (I bought one after Chernobyl.) It was considerably elevated over ground level exposures. However, like an x-ray, you do not continue to be irradiated once at lower levels in the atmosphere. The problem with fallout from a reactor is hot particles inhaled or ingested that continue to irradiate. Being x-rayed, or flying at 35000 feet, involves radiation damage to healthy cells, not continual irradiation for decades (the problem with hot particles).

Is it possible that the fumes are lighter than nitrogen and collect closer to the top of the cabin, selectively affecting people who are standing up for most of the flight? Wildly improbable, I’m guessing, but a possibility.

It might be other gases. Assuming that it is something that is light enough to be something would affect only someone who is standing up most of the time it isn’t out of the question. It might not be something that happens to all 737s but something odd about this particular aircraft.

Regardless, something that causes part of the flight crew to pass out is something that should be figured out.

Unless the cabin crew is out and out lying, there is something that should be looked into here.

Oxygen gas and Nitrogen gas are both diatomic and therefor have atomic weights of 32 and 28 respectively. CO2 is heavier as is any compound with two or more Carbon atoms (plus a few Hydrogen atoms that are always hanging around in hydrocarbons). Water vapor is (relatively) light but I’ve never heard that it hangs around the top of the cabin.

As we have heard many times, the air inside a modern passenger jet is changed 20 or 30 times per hour (or once every two to three minutes) which implies that the air inside the cabin is moving around and well mixed. Stratification sounded like a possibility at first but I don’t think it is the answer.

If you search for it, you can find numerous studies on aircrew exposure to radiation. Bottom line — aircrews do get more exposure than even other “radiation workers”. That is well documented. What seems to be hard to find is much discussion about the actual risk that higher exposure might bring. I did find one study citing a potential increased risk of cataracts:

The problem is that nobody knows what the health effects of low radiation doses is. Say a (high) dose of 2 Sv gives you on average one cancer, and we can measure this. What does 0.02Sv do to you? Does it give you on average 0.01 cancer? (How many people would you need in your study to detect an extra 0.01 cancers against the background of cancers from other causes? How would you account for all the other confounding risk factors?) Alternatively, can your body take such a low dose in its stride and it has no effect?

I’ve been on a number of flights where I smelled exhaust fumes. Usually this is at the gate, shortly before departure. I assume it’s when the engines are turned on and some of the smoke gets into an air intake, or through an open door. Or maybe it’s from a nearby jet. It either quickly dissipates, or my nose gets used to it. My nose is not particularly sensitive, but the smell is unmistakable.

Some news stories about the phenomenon (not to mention the British study) don’t mention Boeing specifically, but American MSM is putting Boeing’s name all over it because that’s who is being sued by the Alaska flight attendants. That’s unfair to Boeing especially since the 787 doesn’t use a bleed-air system for cabin air.